WOT on my primary boat is
- Thread starter BandB
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The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
I chose hull to 12. When I first bought it (used), it would hit 13 knots but since my wife loaded it up ("we need one of these for the boat") I don't think I can hit more than 12. Maybe less.
I cruise at 7 knots. Actually, I cruise at 2000 RPM and take whatever the current gives me. It's been as high as 12 and as low as 3. Slack water is 7.
I cruise at 7 knots. Actually, I cruise at 2000 RPM and take whatever the current gives me. It's been as high as 12 and as low as 3. Slack water is 7.
Wifey B: Yes, the question isn't what we do run but what we can run. This is about the boat, not the user.
Nomad Willy
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We’re only slightly different.
6 knot cruise, 2300rpm and take whatever the current gives me.
Been as high as 11 and as low as 2.
dhays
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Loaded as my boat is, I can to between 11-12 knots. Normal cruise is between 7-8
O C Diver
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While mine isn't a displacement hull, because of the repower it won't exceed hull speed. Think the poll might be more useful if the 3 choices had been:
1. Hull speed and below
2. Plowing (above hull speed and below planing [square root of waterline length x 2])
3. Planing
Ted
1. Hull speed and below
2. Plowing (above hull speed and below planing [square root of waterline length x 2])
3. Planing
Ted
The last time I operated mine at WOT was immediately after the re-power, (June 2000) with the mechanic aboard. I think the speed was about 10 or maybe 10.5. The fwd visibility was hampered by the height of the bow, as the stern had fallen into a deep hole. Why I would ever go to WOT again, I don't know.
At cruise, max speed and min speed are about 8.5 and 7.5.
At cruise, max speed and min speed are about 8.5 and 7.5.
dhays
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Same here. This last summer after the new engine was installed. WOT is loud, expensive, and uncomfortable with the bow reaching for the sky. (Well, not quite as I did use the trim tabs. One of the few times they made a big difference.)
Nomad Willy
Guru
When I first got Willy didn’t go over 6.5 knots.
But I thought I should go WOT to see how she ran and check my prop loading. So I ran her up and only got 2750rpm. Needed 3000. I continued on for about 5 minutes and the engine suddenly quit. I was in a narrow channel and ranout to deploy the anchor. After a few more minutes I started the engine like it didn’t have a problem. It did. But I had no idea it did until I ran WOT.
Henceforth it has been one of my engine checks. Every several months I run WOT for about 5 minutes.
But I thought I should go WOT to see how she ran and check my prop loading. So I ran her up and only got 2750rpm. Needed 3000. I continued on for about 5 minutes and the engine suddenly quit. I was in a narrow channel and ranout to deploy the anchor. After a few more minutes I started the engine like it didn’t have a problem. It did. But I had no idea it did until I ran WOT.
Henceforth it has been one of my engine checks. Every several months I run WOT for about 5 minutes.
Nomad Willy
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Ted to equalize for boat length your #2 would be more specific if it was to read “.8 x hull speed to” something like “1.5 to perhaps 2 x hull speed”.
AusCan
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Displacement hull. My WOT speed with a slack tide and a clean bottom is about 7.5 knots in flat water. In average conditions with 3-5 foot waves I usually lose a knot.
It's fairly rare that I run at WOT. That last 0.5 of a knot doubles both the engine noise and the fuel usage.
It's fairly rare that I run at WOT. That last 0.5 of a knot doubles both the engine noise and the fuel usage.
Wifey B: No problems since they repowered you? It was a PITA but they did step up didn't they?
dhays
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No problems at all and yes, Cummins Northwest really came through. So far 107 hours on the new engine that was put it in July. Having a grandkid for the first time slowed down our boat usage this fall.
The WOT run is part of all scheduled maintenance and is really the only way to know. Even with our desire for speed, we don't regularly run at WOT but we do every time we service the engines.
MurrayM
Guru
WOT on my primary boat is...
pointless.
Could probably get it up on plane with a fusion reactor propulsion unit (I think Mr. Fusion makes one) but 7 knots is about twice as past as we used to sea kayak, so it's all good
pointless.
Could probably get it up on plane with a fusion reactor propulsion unit (I think Mr. Fusion makes one) but 7 knots is about twice as past as we used to sea kayak, so it's all good
During our initial sea trial we ran at WOT for 10 minutes to make sure the boat was propped correctly and also that the engines and cooling systems could handle the heat generated and not let the engines overheat.
WOT is 2130 rpm's and was at 30.3 kts. Don't do that much because we're burning 65 gph. Ouch.
Fast cruise at 80% throttle (~1750 rpm's) yields about 22-24kts.
Hull speed is about 900 rpm's at 9.5kts
Cocktail speed at 500 rpm's yields about 5.5kts.
WOT is 2130 rpm's and was at 30.3 kts. Don't do that much because we're burning 65 gph. Ouch.
Fast cruise at 80% throttle (~1750 rpm's) yields about 22-24kts.
Hull speed is about 900 rpm's at 9.5kts
Cocktail speed at 500 rpm's yields about 5.5kts.
Padeen
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58kts @ WOT
Wifey B: Oh, loved our Cobalt's on the lake, but yours is faster. 640 hp, I'm guessing, on a 29' boat?
Island Cessna
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Not sure because I never run there long enough to verify speed, but I’d guess 7.7 kts.
Great Laker
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Since re-power WOT is 11kn. Previously I could plow at 16.5 kn, and burn 34GPH. I briefly considered increasing engine power rather than reducing it, but knew I would rarely use it.
Even the 200 HP JD's I now have seldom run at more than 1800 rpm/40% load, so have more HP than I need. There were some Mk 1's with twin Lehmans, and although owners might have wanted more speed sometimes, they could run at up to 11 kn as well and were a smart choice for the boat back in the day.
Even the 200 HP JD's I now have seldom run at more than 1800 rpm/40% load, so have more HP than I need. There were some Mk 1's with twin Lehmans, and although owners might have wanted more speed sometimes, they could run at up to 11 kn as well and were a smart choice for the boat back in the day.
kchace
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I clicked on "hull speed to 12 knots" though the boat may do a bit more. I never run at flank speed so I really don't know. Rpm at flank speed on this fully loaded twin Lehman boat is about 2500. Normal cruise is 8-9 knots at 1800 which gets us just about 2mpg. When needed for running an inlet or for other sea state reasons I push it up to 2000-2200 for about 11-12 knots.
Ken
Ken
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